Go to the fourth Cambridgeport History Day. Between noon and 7 p.m. families can go on a free walking tour; talk to costumed re-enactors from the 1812 Marine Guard and thrill to live musket firings; listen to fiddle music and play historic games; enjoy supper at a potluck hosted by the Cambridgeport Neighborhood Association; and more. This year there’s a special focus on the War of 1812, including explorations of how a trade embargo and the war ruined plans for a port in Cambridgeport and the unveiling of a book on neighborhood streets named in honor of 1812 battles and commanders. Start in Dana Park, 10-20 McTernan St., off Pearl Street south of Central Square. More information is here.

Somerville’s Fluff Festival always has more Marshmallow Fluff treats than even the fluffiest eater can handle. (Photo: Rusty Blazenhoff)

Go to the Fluff Festival in Union Square, Somerville. Delicious and horrible Marshmallow Fluff was invented in Somerville in 1917, when a local named Archibald Query invented it in his kitchen and sold it door to door. From 3 to 7 p.m. the Fluff Festival honors the concoction in every way imaginable, including music and burlesque, a cooking contest, games such as Fluff Lick-Off, Blind Man’s Fluff, Fluffer or Nutter Relay, Fluff Hair Dos and Fluff Jousting, a Pharaoh of Fluff contest and, of course, lots of Fluff-related foods, from classic Fluffernutter sandwiches and Rice Krispies treats to Precinct’s Flufflemousse, made with beer by Somerville’s Pretty Things Beer and Ale Project topped with malted Fluff.  More information is here.

Get your comix on at the Massachusetts Independent Comics ExpoLesley University’s Art Institute of Boston is holding its third annual MICE, with panels, workshops and more than 150 exhibitors eager to teach, sell and talk about their alternative comics, ’zines and Web comics with fans and artists of all ages. The popular show takes place from 10 a.m. to 7 p.m. Saturday at University Hall, 1815 Massachusetts Ave., Porter Square. Entry is free. More information is here.

Hurry to the last day of “Marie Antoinette” at the A.R.T. There are still tickets for the 2 p.m. matinee of the funny, scary “Marie Antoinette” at Harvard’s American Repertory Theater, 64 Brattle St., Harvard Square. This is the world premiere of David Adjmi’s play and a staging with revelatory effects no one will forget quickly — evidence that sometimes the sky really is falling. More information is here.

Gross yourself out with a Cockroaches Mini-Exhibit at the Harvard Museum of Natural History. There are — shudder — hands-on activities, dramatic specimen displays, colorful video and graphics and even live animals at the Harvard Museum of Natural History’s “Arthropods: Creatures that Rule” exhibit. Cockroach artist Marc Socie will be on hand between 11 a.m. and noon and 1 and 2 p.m.; museum hours and exhibits are from 9 a.m. to 5 p.m. The spiders have come and gone and it’s the cockroach’s time to rule at 26 Oxford St., between Porter and Harvard squares. General admission includes all exhibits and is free to members and children under 3; $12 for adults; $10 for non-Harvard students with and seniors; $8 for children ages 3 to 18.